U.S. patent application number 17/542294 was filed with the patent office on 2022-06-09 for capacitor-assisted lithium-sulfur battery.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC. The applicant listed for this patent is GM GLOBAL TECHNOLOGY OPERATIONS LLC. Invention is credited to Zhe Li, Haijing Liu, Yong Lu.
Application Number | 20220181710 17/542294 |
Document ID | / |
Family ID | |
Filed Date | 2022-06-09 |
United States Patent
Application |
20220181710 |
Kind Code |
A1 |
Li; Zhe ; et al. |
June 9, 2022 |
CAPACITOR-ASSISTED LITHIUM-SULFUR BATTERY
Abstract
The present disclosure relates to capacitor-assisted
lithium-sulfur batteries including capacitor electrodes and/or
capacitor-based interlayers. For example, a capacitor-assisted
lithium-sulfur battery that includes two or more cells is provided.
Each cell includes at least two electrodes selected from: a first
electrode including a sulfur-containing electroactive material; a
second electrode including a negative electroactive material; a
first capacitor electrode including a positive capacitor active
material; and a second capacitor electrode including a negative
capacitor active material. Each electrode may be disposed adjacent
to a surface of a current collector and a separator may be disposed
between adjacent electrodes so as to provide electrical separation.
One of the two or more cells includes the first electrode and the
second electrode, and no cell includes both the first electrode and
the first capacitor electrode or both the second electrode and the
second capacitor electrode. Each cell may further include at least
one capacitor-based interlayer.
Inventors: |
Li; Zhe; (Shanghai, CN)
; Lu; Yong; (Shanghai, CN) ; Liu; Haijing;
(Shanghai, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM GLOBAL TECHNOLOGY OPERATIONS LLC |
Detroit |
MI |
US |
|
|
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS
LLC
Detroit
MI
|
Appl. No.: |
17/542294 |
Filed: |
December 3, 2021 |
International
Class: |
H01M 10/42 20060101
H01M010/42; H01M 10/0525 20060101 H01M010/0525; H01M 4/38 20060101
H01M004/38; H01M 4/587 20060101 H01M004/587 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 4, 2020 |
CN |
202011404401.5 |
Claims
1. A capacitor-assisted lithium-sulfur battery comprising two or
more cells, wherein each cell comprises at least two electrodes
selected from: a first electrode comprising a sulfur-containing
electroactive material; a second electrode comprising a negative
electroactive material; a first capacitor electrode comprising a
positive capacitor active material; and a second capacitor
electrode comprising a negative capacitor active material, wherein
each electrode is disposed adjacent to a surface of a current
collector and a separator is disposed between adjacent electrodes
so as to provide electrical separation between the first and second
electrodes, the first electrode and the second capacitor electrode,
the second electrode and the first capacitor electrode, and the
first and second capacitor electrodes, wherein one of the two or
more cells includes the first electrode and the second electrode,
and no cell includes both the first electrode and the first
capacitor electrode or both the second electrode and the second
capacitor electrode.
2. The capacitor-assisted lithium-sulfur battery of claim 1,
wherein the first electrode further comprises a sulfur host
material.
3. The capacitor-assisted lithium-sulfur battery of claim 2,
wherein the first electrode comprises greater than or equal to
about 20 wt. % to less than or equal to about 98 wt. % of the
sulfur-containing electroactive material, and greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. % of the
sulfur host material.
4. The capacitor-assisted lithium-sulfur battery of claim 2,
wherein the sulfur host material is selected from the group
consisting of: carbon nanotubes, amorphous carbon, porous carbon,
carbon nanofibers, carbon spheres, carbon nanocage, graphene,
graphene oxide, reduced graphene oxide, doped carbon, polyaniline
(PAN), polypyrrole (PPy), polythiophene (Pt), polyaniline (PAni),
poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS),
TiO.sub.2, SiO.sub.2, CoS.sub.2, Ti.sub.4O.sub.7, CeO.sub.2,
MoO.sub.3, V.sub.2O.sub.5, SnO.sub.2, Ni.sub.3S.sub.2, MoS.sub.2,
FeS, VS.sub.2, TiS.sub.2, TiS, CoS.sub.2, Co.sub.9S.sub.8, NbS, VN,
TiN, Ni.sub.2N, CrN, ZrN, NbN, TiC, Ti.sub.2C, B.sub.4C,
Ni-based-MOFs, Ce-based-MOFs, polypyrrole/graphene, vanadium
nitride/graphene, MgB.sub.2, TiCl.sub.2, phosphorene, C.sub.3B,
Li.sub.4Ti.sub.5O.sub.12, and combinations thereof.
5. The capacitor-assisted lithium-sulfur battery of claim 1,
wherein the negative electroactive material comprises lithium
metal.
6. The capacitor-assisted lithium-sulfur battery of claim 1,
wherein the positive capacitor active material is selected from the
group consisting of: activated carbon, graphene, carbon nanotubes,
other porous carbon materials, conducting polymers, and
combinations thereof.
7. The capacitor-assisted lithium-sulfur battery of claim 1,
wherein the negative capacitor active material is selected from the
group consisting of: lithiated activated carbon, lithiated soft
carbon, lithiated hard carbon, lithiated metal oxides, lithiated
metal sulfides, and combinations thereof.
8. The capacitor-assisted lithium-sulfur battery of claim 1,
wherein each cell comprises the first electrode and the second
electrode, and wherein each cell further comprises at least one
capacitor-based interlayer.
9. The capacitor-assisted lithium-sulfur battery of claim 8,
wherein the at least one capacitor-based interlayer is disposed
between the first electrode and the separator.
10. The capacitor-assisted lithium-sulfur battery of claim 9,
wherein the at least one capacitor-based interlayer comprises a
positive capacitor active material, wherein the positive capacitor
active material is selected from the group consisting of activated
carbon, graphene, carbon nanotubes, other porous carbon materials,
conducting polymers, and combinations thereof.
11. The capacitor-assisted lithium-sulfur battery of claim 8,
wherein the at least one capacitor-based interlayer is disposed
between the second electrode and the separator.
12. The capacitor-assisted lithium-sulfur battery of claim 11,
wherein the at least one capacitor-based interlayer comprises a
negative capacitor active material, wherein the negative capacitor
active material is selected from the group consisting of: lithiated
activated carbon, lithiated soft carbon, lithiated hard carbon,
lithiated metal oxides, lithiated metal sulfides, and combinations
thereof.
13. The capacitor-assisted lithium-sulfur battery of claim 8,
wherein the at least one capacitor-based interlayer comprises a
first capacitor-based layer and a second capacitor-based layer,
wherein the first capacitor-based layer is disposed between the
first electrode and the separator and the second capacitor-based
interlayer is disposed between the second electrode and the
separator, and wherein the first capacitor-based layer is a
positive capacitor-based layer and the second capacitor-based
interlayer is a negative capacitor-based layer.
14. The capacitor-assisted lithium-sulfur battery of claim 8,
wherein the at least one capacitor-based layer has a thickness
greater than or equal to about 0.1 .mu.m to less than or equal to
about 100 .mu.m.
15. A capacitor-assisted lithium-sulfur electrochemical cell
comprising: a first current collector having a first surface; a
first electrode disposed adjacent to the first surface of the first
current collector, the first electrode comprising a
sulfur-containing electroactive material; a second current
collector having a first surface, wherein the first surface of the
second current collector is substantially parallel with the first
surface of first current collector; a capacitor electrode disposed
adjacent to the first surface of the second current collector,
wherein the capacitor electrode comprises a negative capacitor
active material; and a separator disposed between the first
electrode and the capacitor electrode.
16. The capacitor-assisted lithium-sulfur electrochemical cell of
claim 15, wherein the first electrode further greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. % of a
sulfur host material.
17. The capacitor-assisted lithium-sulfur electrochemical cell of
claim 15, wherein the negative capacitor active material is
selected from the group consisting of: lithiated activated carbon,
lithiated soft carbon, lithiated hard carbon, lithiated metal
oxides, lithiated metal sulfides, and combinations thereof.
18. A capacitor-assisted lithium-sulfur electrochemical cell
comprising: a first current collector having a first surface; a
first electrode disposed adjacent to the first surface of the first
current collector, wherein the first electrode comprises a
sulfur-containing electroactive material; a second current
collector having a first surface, wherein the first surface of the
second current collector is substantially parallel with the first
surface of first current collector; a second electrode disposed
adjacent to the first surface of the second current collector; a
separator disposed between the first and second electrodes; and a
capacitor-based interlayer disposed between one of the first
electrode and the separator or the second electrode and the
separator, wherein the capacitor-based interlayer has a thickness
greater than or equal to about 0.1 .mu.m to less than or equal to
about 100 .mu.m.
19. The capacitor-assisted lithium-sulfur electrochemical cell of
claim 18, wherein the capacitor-based interlayer is disposed
between the first electrode and the separator, wherein the
capacitor-based interlayer comprises a positive capacitor active
material, wherein the positive capacitor active material is
selected from the group consisting of: activated carbon, graphene,
carbon nanotubes, other porous carbon materials, conducting
polymers, and combinations thereof.
20. The capacitor-assisted lithium-sulfur electrochemical cell of
claim 18, wherein the capacitor-based interlayer is disposed
between the second electrode and the separator, wherein the
capacitor-based interlayer comprises a negative capacitor active
material, wherein the negative capacitor active material is
selected from the group consisting of: lithiated activated carbon,
lithiated soft carbon, lithiated hard carbon, lithiated metal
oxides, lithiated metal sulfides, and combinations thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit and priority of Chinese
Patent Application No. 202011404401.5, filed Dec. 4, 2020. The
entire disclosure of the above application is incorporated herein
by reference.
INTRODUCTION
[0002] This section provides background information related to the
present disclosure which is not necessarily prior art.
[0003] Advanced energy storage devices and systems are in demand to
satisfy energy and/or power requirements for a variety of products,
including automotive products such as start-stop systems (e.g., 12V
start-stop systems), battery-assisted systems, Hybrid Electric
Vehicles ("HEVs"), and Electric Vehicles ("EVs"). Lithium-sulfur
batteries can deliver high energy densities (e.g., up to about 2500
Wh/kg) and are generally available at lower costs and are
environmentally friendly. In certain instances, however,
lithium-sulfur batteries may have limited rate capabilities, for
example, as a result of the insulating nature of sulfur and its
reduction products (e.g., in the form of Li.sub.2S and/or
Li.sub.2S.sub.2). Accordingly, it would be desirable to develop
materials and systems having both high energy densities and
increased power capabilities.
SUMMARY
[0004] This section provides a general summary of the disclosure,
and is not a comprehensive disclosure of its full scope or all of
its features.
[0005] The present disclosure relates to a capacitor-assisted
lithium-sulfur battery including one or more capacitor electrodes
and/or one or more capacitor-based interlayers.
[0006] In various aspects, the present disclosure provides a
capacitor-assisted lithium-sulfur battery that includes two or more
cells. Each cell includes at least two electrodes selected from: a
first electrode including a sulfur-containing electroactive
material; a second electrode including a negative electroactive
material; a first capacitor electrode including a positive
capacitor active material; and a second capacitor electrode
including a negative capacitor active material. Each electrode may
be disposed adjacent to a surface of a current collector and a
separator may be disposed between adjacent electrodes so as to
provide electrical separation between the first and second
electrodes, the first electrode and the second capacitor electrode,
the second electrode and the first capacitor electrode, and the
first and second capacitor electrodes. One of the two or more cells
includes the first electrode and the second electrode, and no cell
includes both (together) the first electrode and the first
capacitor electrode or both (together) the second electrode and the
second capacitor electrode.
[0007] In one aspect, the first electrode may further include a
sulfur host material.
[0008] In one aspect, the first electrode includes greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. % of
the sulfur-containing electroactive material, and greater than or
equal to about 2 wt. % to less than or equal to about 60 wt. % of
the sulfur host material.
[0009] In one aspect, the sulfur host material may be selected from
the group consisting of: carbon nanotubes, amorphous carbon, porous
carbon, carbon nanofibers, carbon spheres, carbon nanocage,
graphene, graphene oxide, reduced graphene oxide, doped carbon,
polyaniline (PAN), polypyrrole (PPy), polythiophene (Pt),
polyaniline (PAni),
poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS),
TiO.sub.2, SiO.sub.2, CoS.sub.2, Ti.sub.4O.sub.7, CeO.sub.2,
MoO.sub.3, V.sub.2O.sub.5, SnO.sub.2, Ni.sub.3S.sub.2, MoS.sub.2,
FeS, VS.sub.2, TiS.sub.2, TiS, CoS.sub.2, Co.sub.9S.sub.8, NbS, VN,
TiN, Ni.sub.2N, CrN, ZrN, NbN, TiC, Ti.sub.2C, B.sub.4C,
Ni-based-MOFs, Ce-based-MOFs, polypyrrole/graphene, vanadium
nitride/graphene, MgB.sub.2, TiCl.sub.2, phosphorene, C.sub.3B,
Li.sub.4Ti.sub.5O.sub.12, and combinations thereof.
[0010] In one aspect, the negative electroactive material includes
lithium metal.
[0011] In one aspect, the positive capacitor active material may be
selected from the group consisting of: activated carbon, graphene,
carbon nanotubes, other porous carbon materials, conducting
polymers, and combinations thereof.
[0012] In one aspect, the negative capacitor active material may be
selected from the group consisting of: lithiated activated carbon,
lithiated soft carbon, lithiated hard carbon, lithiated metal
oxides, lithiated metal sulfides, and combinations thereof.
[0013] In one aspect, each cell includes the first electrode and
the second electrode, and each cell may further include at least
one capacitor-based interlayer.
[0014] In one aspect, the at least one capacitor-based interlayer
may be disposed between the first electrode and the separator.
[0015] In one aspect, the at least one capacitor-based interlayer
may include a positive capacitor active material. The positive
capacitor active material may be selected from the group consisting
of: activated carbon, graphene, carbon nanotubes, other porous
carbon materials, conducting polymers, and combinations
thereof.
[0016] In one aspect, the at least one capacitor-based interlayer
may be disposed between the second electrode and the separator.
[0017] In one aspect, the at least one capacitor-based interlayer
may include a negative capacitor active material. The negative
capacitor active material may be selected from the group consisting
of lithiated activated carbon, lithiated soft carbon, lithiated
hard carbon, lithiated metal oxides, lithiated metal sulfides, and
combinations thereof.
[0018] In one aspect, the at least one capacitor-based interlayer
may include a first capacitor-based layer and a second
capacitor-based layer. The first capacitor-based layer may be
disposed between the first electrode and the separator. The second
capacitor-based interlayer may be disposed between the second
electrode and the separator. The first capacitor-based layer may be
a positive capacitor-based layer. The second capacitor-based
interlayer may be a negative capacitor-based layer.
[0019] In one aspect, the at least one capacitor-based layer may
have a thickness greater than or equal to about 0.1 .mu.m to less
than or equal to about 100 .mu.m.
[0020] In various aspects, the present disclosure provides a
capacitor-assisted lithium-sulfur electrochemical cell. The
capacitor-assisted lithium-sulfur electrochemical cell may include
a first current collector having a first surface; a first electrode
disposed adjacent to the first surface of the first current
collector; a second current collector having a first surface, where
the first surface of the second current collector is substantially
parallel with the first surface of first current collector; a
capacitor electrode disposed adjacent to the first surface of the
second current collector; and a separator disposed between the
first electrode and the capacitor electrode. The first electrode
may include a sulfur-containing electroactive material. The
capacitor electrode may include a negative capacitor active
material.
[0021] In one aspect, the first electrode may include greater than
or equal to about 2 wt. % to less than or equal to about 60 wt. %
of a sulfur host material.
[0022] In one aspect, the negative capacitor active material may be
selected from the group consisting of: lithiated activated carbon,
lithiated soft carbon, lithiated hard carbon, lithiated metal
oxides, lithiated metal sulfides, and combinations thereof.
[0023] In various aspects, the present disclosure provides a
capacitor-assisted lithium-sulfur electrochemical cell. The
capacitor-assisted lithium-sulfur electrochemical cell may include
a first current collector having a first surface; a first electrode
disposed adjacent to the first surface of the first current
collector; a second current collector having a first surface, where
the first surface of the second current collector is substantially
parallel with the first surface of first current collector; a
second electrode disposed adjacent to the first surface of the
second current collector; a separator disposed between the first
and second electrodes; and a capacitor-based interlayer disposed
between one of the first electrode and the separator or the second
electrode and the separator. The first electrode may include a
sulfur-containing electroactive material. The capacitor-based
interlayer may have a thickness greater than or equal to about 0.1
.mu.m to less than or equal to about 100 .mu.m.
[0024] In one aspect, the capacitor-based interlayer may be
disposed between the first electrode and the separator. The
capacitor-based interlayer may include a positive capacitor active
material. The positive capacitor active material may be selected
from the group consisting of: activated carbon, graphene, carbon
nanotubes, other porous carbon materials, conducting polymers, and
combinations thereof.
[0025] In one aspect, the capacitor-based interlayer may be
disposed between the second electrode and the separator. The
capacitor-based interlayer may include a negative capacitor active
material. The negative capacitor active material may be selected
from the group consisting of lithiated activated carbon, lithiated
soft carbon, hard carbon, lithiated metal oxides, lithiated metal
sulfides, and combinations thereof.
[0026] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples
in this summary are intended for purposes of illustration only and
are not intended to limit the scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0028] FIG. 1 is a schematic of an example electrochemical battery
cell including a lithium-ion capacitor cathode;
[0029] FIG. 2 is a schematic of an example electrochemical battery
cell including a lithium-ion capacitor anode;
[0030] FIG. 3 is a schematic of an example electrochemical battery
cell including an electric double-layer capacitor (EDLC);
[0031] FIG. 4 is a schematic of an example electrochemical battery
cell having an asymmetric cathode;
[0032] FIG. 5 is a schematic of an example electrochemical battery
cell having an asymmetric anode;
[0033] FIG. 6 is a schematic of an example electrochemical battery
cell having a capacitor-based interlayer disposed between a cathode
and a separator;
[0034] FIG. 7 is a schematic of an example electrochemical battery
cell having a capacitor-based interlayer disposed between an anode
and a separator; and
[0035] FIG. 8 is a schematic of an example electrochemical battery
cell having a first capacitor-based interlayer disposed between a
cathode and a separator and a second capacitor-based interlayer
disposed between an anode and the separator.
[0036] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0037] Example embodiments are provided so that this disclosure
will be thorough, and will fully convey the scope to those who are
skilled in the art. Numerous specific details are set forth such as
examples of specific compositions, components, devices, and
methods, to provide a thorough understanding of embodiments of the
present disclosure. It will be apparent to those skilled in the art
that specific details need not be employed, that example
embodiments may be embodied in many different forms and that
neither should be construed to limit the scope of the disclosure.
In some example embodiments, well-known processes, well-known
device structures, and well-known technologies are not described in
detail.
[0038] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting. As used herein, the singular forms "a," "an," and "the"
may be intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises,"
"comprising," "including," and "having," are inclusive and
therefore specify the presence of stated features, elements,
compositions, steps, integers, operations, and/or components, but
do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
groups thereof. Although the open-ended term "comprising," is to be
understood as a non-restrictive term used to describe and claim
various embodiments set forth herein, in certain aspects, the term
may alternatively be understood to instead be a more limiting and
restrictive term, such as "consisting of" or "consisting
essentially of" Thus, for any given embodiment reciting
compositions, materials, components, elements, features, integers,
operations, and/or process steps, the present disclosure also
specifically includes embodiments consisting of, or consisting
essentially of, such recited compositions, materials, components,
elements, features, integers, operations, and/or process steps. In
the case of "consisting of," the alternative embodiment excludes
any additional compositions, materials, components, elements,
features, integers, operations, and/or process steps, while in the
case of "consisting essentially of," any additional compositions,
materials, components, elements, features, integers, operations,
and/or process steps that materially affect the basic and novel
characteristics are excluded from such an embodiment, but any
compositions, materials, components, elements, features, integers,
operations, and/or process steps that do not materially affect the
basic and novel characteristics can be included in the
embodiment.
[0039] Any method steps, processes, and operations described herein
are not to be construed as necessarily requiring their performance
in the particular order discussed or illustrated, unless
specifically identified as an order of performance. It is also to
be understood that additional or alternative steps may be employed,
unless otherwise indicated.
[0040] When a component, element, or layer is referred to as being
"on," "engaged to," "connected to," or "coupled to" another element
or layer, it may be directly on, engaged, connected or coupled to
the other component, element, or layer, or intervening elements or
layers may be present. In contrast, when an element is referred to
as being "directly on," "directly engaged to," "directly connected
to," or "directly coupled to" another element or layer, there may
be no intervening elements or layers present. Other words used to
describe the relationship between elements should be interpreted in
a like fashion (e.g., "between" versus "directly between,"
"adjacent" versus "directly adjacent," etc.). As used herein, the
term "and/or" includes any and all combinations of one or more of
the associated listed items.
[0041] Although the terms first, second, third, etc. may be used
herein to describe various steps, elements, components, regions,
layers and/or sections, these steps, elements, components, regions,
layers and/or sections should not be limited by these terms, unless
otherwise indicated. These terms may be only used to distinguish
one step, element, component, region, layer or section from another
step, element, component, region, layer or section. Terms such as
"first," "second," and other numerical terms when used herein do
not imply a sequence or order unless clearly indicated by the
context. Thus, a first step, element, component, region, layer or
section discussed below could be termed a second step, element,
component, region, layer or section without departing from the
teachings of the example embodiments.
[0042] Spatially or temporally relative terms, such as "before,"
"after," "inner," "outer," "beneath," "below," "lower," "above,"
"upper," and the like, may be used herein for ease of description
to describe one element or feature's relationship to another
element(s) or feature(s) as illustrated in the figures. Spatially
or temporally relative terms may be intended to encompass different
orientations of the device or system in use or operation in
addition to the orientation depicted in the figures.
[0043] Throughout this disclosure, the numerical values represent
approximate measures or limits to ranges to encompass minor
deviations from the given values and embodiments having about the
value mentioned as well as those having exactly the value
mentioned. Other than in the working examples provided at the end
of the detailed description, all numerical values of parameters
(e.g., of quantities or conditions) in this specification,
including the appended claims, are to be understood as being
modified in all instances by the term "about" whether or not
"about" actually appears before the numerical value. "About"
indicates that the stated numerical value allows some slight
imprecision (with some approach to exactness in the value;
approximately or reasonably close to the value; nearly). If the
imprecision provided by "about" is not otherwise understood in the
art with this ordinary meaning, then "about" as used herein
indicates at least variations that may arise from ordinary methods
of measuring and using such parameters. For example, "about" may
comprise a variation of less than or equal to 5%, optionally less
than or equal to 4%, optionally less than or equal to 3%,
optionally less than or equal to 2%, optionally less than or equal
to 1%, optionally less than or equal to 0.5%, and in certain
aspects, optionally less than or equal to 0.1%.
[0044] In addition, disclosure of ranges includes disclosure of all
values and further divided ranges within the entire range,
including endpoints and sub-ranges given for the ranges.
[0045] Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0046] The present technology pertains to improved electrochemical
cells that include one or more capacitor components or additives
and that may be incorporated into energy storage devices, for
example lithium-sulfur batteries. Such electrochemical cells may
have hybrid structures, so as to integrate the high power
capability capacitors with the high energy density of
lithium-sulfur batteries. In various instances the electrochemical
cells and energy storage devices may be used in, for example,
automotive or other vehicles (e.g., motorcycles, boats tractors,
buses, motorcycles, mobile homes, campers, and tanks). However, the
described electrochemical cells and energy storage devices
incorporating such electrochemical cells may also be used in a
variety of other industries and applications, including aerospace
components, consumer goods, devices, buildings (e.g., houses,
offices, sheds, and warehouses), office equipment and furniture,
and industrial equipment machinery, agricultural or farm equipment,
or heavy machinery, by way of non-limiting example.
[0047] Typical lithium-sulfur batteries include a first electrode
(such as a positive sulfur electrode or sulfur cathode) opposing a
second electrode (such as a lithium negative electrode or lithium
anode) and a separator and/or electrolyte disposed therebetween.
The first and second electrodes are connected, respectively, to
first and second current collectors (typically a metal, such as
copper for the anode and aluminum for the cathode). The current
collectors associated with the two electrodes are connected by an
external circuit that allows current generated by electrons to pass
between the electrodes to compensate for transport of lithium ions
across the battery cell. For example, during cell discharge, the
internal lithium ion (Li) ionic current from the negative electrode
to the positive electrode may be compensated by the electronic
current flowing through the external circuit from the negative
electrode to the positive electrode of the battery cell. The
electrolyte is suitable for conducting lithium ions and, in various
aspects, may be in liquid, gel, or solid form.
[0048] In various aspects, multiple lithium-sulfur battery cells
may be electrically connected in an electrochemical device to
increase overall output. For example, lithium-sulfur battery cells
may be electrically coupled in a stack or winding configuration to
increase overall output. Stacks often include positioning first and
second current collectors and corresponding first and second
electrodes in alternating arrangements with a separator and/or
electrolyte disposed between the electrodes. The current collectors
may be electrically connected in a serial or parallel arrangements.
In the instance of hybridized or capacitor-assisted lithium-sulfur
batteries, a capacitor material that serves a capacitor function
may be integrated into the cell stack. For example, in various
aspects, the capacitor-assisted batteries may include one or more
capacitor components or layers that are parallel or stacked with
the one or more of the electrodes of the battery.
[0049] Such capacitor-assisted lithium-sulfur batteries may provide
several advantages, such as power response, as well as improved
long-term performance. For example, power response may be improved
by incorporating capacitor component layers or materials. Each of
the electrodes, including positive and negative electrodes and
capacitor electrodes, within a hybrid battery pack or cell may be
electrically connected to a current collector. During battery
usage, the current collectors associated with the electrodes are
connected by an external circuit that allows current generated by
electrons to pass between the electrodes to compensate for
transport of lithium ions.
[0050] An exemplary and schematic illustration of an example
capacitor-assisted lithium-sulfur cell (also referred to as the
battery) 20 is shown in FIG. 1. The capacitor-assisted
lithium-sulfur battery 20 includes a plurality of cells 10A-10C.
Though only three cells are illustrated, the skilled artisan will
understand that the present teachings apply to various other
battery configurations, including batteries having fewer or more
cells, as illustrated by the ellipsis. Each cell 10A-10C includes a
negative electrode 22 (e.g., anode), a positive electrode 24 (e.g.,
cathode), and a separator 26 disposed between the two electrodes
22, 24. At least one of the cells 10A-10C, includes a capacitor
electrode (e.g., lithium-ion capacitor cathode) 30 in place of one
of the electrodes 22, 24. For example, as illustrated, a capacitor
electrode 30 may be disposed in place of the cathode 24 in a first
cell 10A. In each instance, the separator 26 provides electrical
separation (e.g., prevents physical contact) between the electrodes
22, 24, 30. The separator 26 also provides a minimal resistance
path for internal passage of lithium ions, and in certain
instances, related anions, during cycling of the lithium ions. In
various aspects, the separator 26 comprises an electrolyte 100 that
may, in certain aspects, also be present in the negative electrode
22, positive electrode 24, and/or capacitor electrode 30. In
certain variations, the separator 26 may be formed by a solid-state
electrolyte. For example, the separator 26 may be defined by a
plurality of solid-state electrolyte particles (not shown).
[0051] A negative electrode current collector 32 may be positioned
at or near each negative electrode 22, and a positive electrode
current collector 34 may be positioned at or near each positive
electrode 24 and/or capacitor electrode 30. The negative electrode
current collectors 32 and the positive electrode current collectors
34 respectively collect and move free electrons to and from an
external circuit 40. For example, an interruptible external circuit
40 and a load device 42 may connect the negative electrodes 22
(through the negative electrode current collectors 32) and the
positive electrodes 24 and/or capacitor electrodes 30 (through the
positive electrode current collectors 34).
[0052] The negative electrode current collectors 32 may be metal
foils, metal grids or screens, or expanded metals comprising copper
or any other appropriate electrically conductive material known to
those of skill in the art (such as, for example only, aluminum,
nickel, iron, titanium tin, and the like). The negative electrode
current collectors 32 may have thicknesses greater than or equal to
about 4 .mu.m to less than or equal to about 100 .mu.m.
[0053] The positive electrode current collectors 34 may be metal
foils, metal grids or screens, or expanded metals comprising
aluminum or any other appropriate electrically conductive material
known to those of skill in the art (such as, for example only,
copper, stainless steel, nickel, iron, titanium, and tin, and the
like). For example, in certain aspects, the positive electrode
current collectors 34 may be two-dimensional current collectors
having thicknesses greater than or equal to about 4 .mu.m to less
than or equal to about 100 .mu.m and comprising, for example only,
aluminum, carbon-coated aluminum, stainless steel, nickel, iron,
titanium, copper, tin, and other like conductive materials. In
other variations, the positive electrode current collectors 34 may
be three-dimensional current collectors having thickness greater
than or equal to about 4 .mu.m to less than or equal to about 2000
.mu.m and comprising, for example only, meshed current collector,
aluminum foam, nickel foam, copper foam, carbon nanofiber
three-dimensional current collector, graphene foam, carbon cloth,
carbon fiber-embedded carbon nanotubes, carbon nanotubes
three-dimensional current collector (such as, carbon nanotube
paper), graphene/nickel foam, and the like.
[0054] Though not illustrated, the skilled artisan will appreciate
that the present teachings also apply to various other electrode
configurations, including for example, capacitor-assisted
lithium-sulfur batteries comprising one or more additional negative
electrodes, one or more additional positive electrodes, and one or
more additional capacitor, capacitor-assisted, or composite
electrodes. In each instance, the capacitor-assisted batteries
include alternating stacks of negative electrodes interspaced by
the positive electrodes or positive capacitor electrodes or stacks
of positive electrodes interspaced by negative electrodes or
negative capacitor electrodes.
[0055] The battery 20 can generate an electric current during
discharge by way of reversible electrochemical reactions that occur
when the external circuit 40 is closed (to connect the negative
electrodes 22 and the positive electrodes 24 and/or the capacitor
electrodes 30) and the negative electrodes 22 have a lower
potential than the positive electrodes 24. In each instance, the
chemical potential difference between the positive electrodes 24
and the negative electrodes 22 drives electrons produced by a
reaction, for example, the oxidation of lithium (e.g., lithium
metal), at the negative electrodes 22 through the external circuit
40 towards the positive electrodes 24 and/or capacitor electrodes
30. Lithium ions that are produced at the negative electrodes 22
are concurrently transferred through the electrolyte 100 contained
in the separator 26 towards the positive electrodes 24 and/or
capacitor electrodes 30. The electrons flow through the external
circuit 40 and the lithium ions migrate across the separator 26
containing the electrolyte 100 to form Li.sub.2S and/or
Li.sub.2S.sub.2 at the positive electrodes 24, for example step by
step and/or to be adsorbed by the capacitor electrode 30. As noted
above, electrolyte 100 is typically also present in the negative
electrode 22 and positive electrode 24. The electric current
passing through the external circuit 40 can be harnessed and
directed through the load device 42 until the capacity of the
battery 20 is diminished.
[0056] The battery 20 can be charged or re-energized at any time by
connecting an external power source to the battery 20 to reverse
the electrochemical reactions that occur during battery discharge.
Connecting an external electrical energy source to the battery 20
promotes a reaction, for example, non-spontaneous oxidation of
Li.sub.2S and/or Li.sub.2S.sub.2, at the positive electrode 24
and/or the desorption of Li.sup.+ at capacitor electrodes 30 so
that electrons and lithium ions are produced. The lithium ions flow
back towards the negative electrodes 22 through the electrolyte 100
across the separator 26 to replenish the negative electrodes 22
with lithium for use during the next battery discharge event. As
such, a complete discharging event followed by a complete charging
event is considered to be a cycle, where lithium ions are cycled
between the positive electrodes 24 and/or capacitor electrodes 30
and the negative electrode 22. The external power source that may
be used to charge the battery 20 may vary depending on the size,
construction, and particular end-use of the battery 20. Some
notable and exemplary external power sources include, but are not
limited to, an AC-DC converter connected to an AC electrical power
grid though a wall outlet and a motor vehicle alternator.
[0057] In many battery 20 configurations, each of the negative
electrode current collectors 32, negative electrodes 22, separators
26, positive electrodes 24, positive electrode current collectors
34, and capacitor electrodes 30 can be prepared as relatively thin
layers (for example, from several microns to a fraction of a
millimeter or less in thickness) and assembled in layers connected
in electrical parallel arrangement to provide a suitable electrical
energy and power package. In various aspects, the battery 20 may
also include a variety of other components that, while not depicted
here, are nonetheless known to those of skill in the art. For
instance, the battery 20 may include a casing, gaskets, terminal
caps, tabs, battery terminals, and any other conventional
components or materials that may be situated within the battery 20,
including between or around the negative electrodes 22, the
positive electrodes 24, capacitor electrodes 30, and/or the
separator 26. The battery 20 shown in FIG. 1 includes a liquid
electrolyte 100 and shows representative concepts of battery
operation. However, the current technology also applies to
solid-state batteries that include solid-state electrolytes and
solid-state electroactive particles that may have a different
design, as known to those of skill in the art.
[0058] As noted above, the size and shape of the battery 20 may
vary depending on the particular application for which it is
designed. Battery-powered vehicles and hand-held consumer
electronic devices, for example, are two examples where the battery
20 would most likely be designed to different size, capacity, and
power-output specifications. The battery 20 may also be connected
in series or parallel with other similar lithium-ion and/or
lithium-sulfur cells or batteries to produce a greater voltage
output, energy, and power if it is required by the load device 42.
Accordingly, the battery 20 can generate electric current to a load
device 42 that is part of the external circuit 40. The load device
42 may be powered by the electric current passing through the
external circuit 40 when the battery 20 is discharging. While the
electrical load device 42 may be any number of known
electrically-powered devices, a few specific examples include an
electric motor for an electrified vehicle, a laptop computer, a
tablet computer, a cellular phone, and cordless power tools or
appliances. The load device 42 may also be an
electricity-generating apparatus that charges the battery 20 for
purposes of storing electrical energy.
[0059] With renewed reference to FIG. 1, the positive electrode 24,
the negative electrode 22, the capacitor electrodes 30, and the
separator 26 may each include an electrolyte solution or system 100
inside their pores that is capable of conducting lithium ions
between the negative electrodes 22 and the positive electrodes 24
and/or capacitor electrodes 30. Any appropriate electrolyte 100,
whether in solid, liquid, or gel form, capable of conducting
lithium ions between the negative electrodes 22 and the positive
electrodes 24 and/or capacitor electrodes 30 may be used in the
battery 20. In certain aspects, the electrolyte 100 may be a
non-aqueous liquid electrolyte solution that includes a lithium
salt dissolved in an organic solvent or a mixture of organic
solvents. In certain variations, the electrolyte 100 may further
include one or more additives. For example, the electrolyte 100 may
include greater than or equal to about 0.01 M to less than or equal
to about 1.0 M of the one or more additives. The one or more
additives may include, for example only, LiNO.sub.3,
Li.sub.2S.sub.x (where 4.ltoreq.x.ltoreq.8), P.sub.2S.sub.5,
phosphorus-containing flame retardant additives (e.g.,
tris(2,2,2-trifluoroethyl)phosphite (TTFP)), redox mediators (e.g.,
LiI), and the like. Numerous conventional non-aqueous liquid
electrolyte 100 solutions may be employed in the battery 20.
[0060] In certain aspects, the electrolyte 100 may be a non-aqueous
liquid electrolyte solution that includes one or more lithium salts
(e.g., greater than or equal to about 0.5 M to less than or equal
to about 20 M) dissolved in an organic solvent or a mixture of
organic solvents. For example, a non-limiting list of lithium salts
that may be dissolved in an organic solvent to form the non-aqueous
liquid electrolyte solution include lithium
bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium
bis(pentafluoroethanesulfonyl)imide (LiBETI) lithium
hexafluorophosphate (LiPF.sub.6), lithium perchlorate
(LiClO.sub.4), lithium tetrachloroaluminate (LiAlCl.sub.4), lithium
iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN),
lithium tetrafluoroborate (LiBF.sub.4), lithium tetraphenylborate
(LiB(C.sub.6Hs).sub.4), lithium bis(oxalato)borate
(LiB(C.sub.2O.sub.4).sub.2) (LiBOB), lithium difluorooxalatoborate
(LiBF.sub.2(C.sub.2O.sub.4)), lithium hexafluoroarsenate
(LiAsF.sub.6), lithium trifluoromethanesulfonate
(LiCF.sub.3SO.sub.3), lithium bis(trifluoromethane)sulfonylimide
(LiN(CF.sub.3SO.sub.2).sub.2), lithium bis(fluorosulfonyl)imide
(LiN(FSO.sub.2).sub.2) (LiSFI), and combinations thereof.
[0061] These and other similar lithium salts may be dissolved in a
variety of non-aqueous aprotic organic solvents, including, but not
limited to, various alkyl carbonates, such as cyclic carbonates
(e.g., ethylene carbonate (EC), propylene carbonate (PC), butylene
carbonate (BC), fluoroethylene carbonate (FEC)), linear carbonates
(e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC),
ethylmethylcarbonate (EMC)), aliphatic carboxylic esters (e.g.,
methyl formate, methyl acetate, methyl propionate),
.gamma.-lactones (e.g., .gamma.-butyrolactone,
.gamma.-valerolactone), chain structure ethers (e.g.,
1,2-dimethoxyethane (DME), 1-2-diethoxyethane,
ethoxymethoxyethane), cyclic ethers (e.g., tetrahydrofuran,
2-methyltetrahydrofuran, 1,3-dioxolane (DOL)), sulfur compounds
(e.g., sulfolane), fluorinated ethers (e.g.,
1,1,2,2-tetrafluoroethyle 2,2,3,3-tetrafluoropropyl ether (HFE)),
aprotic ionic liquid (e.g., N-methyl-N-butylpiperidinium
bis(trifluoromethanesulfonyl)amid ([PP14][TFSI])), solvate ionic
liquid (e.g., tetraglyme (G4)), and combinations thereof.
[0062] In certain aspects, example electrolyte systems 100 include
1M lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) in
1,3-dioxolane (DOL)/1,2-dimethoxyethane (DME) (1:1 v/v), 1M lithium
bis(trifluoromethylsulfonyl)imide (LiTFSI) in 1,3-dioxolane
(DOL)/1,2-dimethoxyethane (DME) (1:1 v/v) with 0.1M LiNO.sub.3, and
1.0M lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) in
1,3-dioxolane (DOL)/1,1,2,2-tetrafluoroethyle
2,2,3,3-tetrafluoropropyl ether (HFE) (1:2 v/v), by way of
non-limiting example. In other variations, example electrolyte
systems 100 are concentrated electrolytes including, for example
only, 7M lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) in
1,2-dimethoxyethane (DME)/1,3-dioxolane (DOL), 1M lithium
bis(trifluoromethylsulfonyl)imide (LiTFSI) in
N-methyl-N-butylpiperidinium bis(trifluoromethanesulfonyl)amid
([PP14][TFSI]), [Li(G4)][TFSI]/4(1,1,2,2-tetrafluoroethyle
2,2,3,3-tetrafluoropropyl ether (HFE)), 0.2M LiOH aqueous solution,
and the like.
[0063] The separator 26 may be a porous separator having a porosity
greater than or equal to about 30 vol. % to less than or equal to
about 80%. The separator 26 may be, in certain instances, a
microporous polymeric separator including a polyolefin. The
polyolefin may be a homopolymer (derived from a single monomer
constituent) or a heteropolymer (derived from more than one monomer
constituent), which may be either linear or branched. If a
heteropolymer is derived from two monomer constituents, the
polyolefin may assume any copolymer chain arrangement, including
those of a block copolymer or a random copolymer. Similarly, if the
polyolefin is a heteropolymer derived from more than two monomer
constituents, it may likewise be a block copolymer or a random
copolymer. In certain aspects, the polyolefin may be polyethylene
(PE), polypropylene (PP), or a blend of polyethylene (PE) and
polypropylene (PP), or multi-layered structured porous films of
polyethylene (PE) and/or polypropylene (PP). Commercially available
polyolefin porous separator membranes include CELGARD.RTM. 2500 (a
monolayer polypropylene separator) and CELGARD.RTM.2320 (a trilayer
polypropylene/polyethylene/polypropylene separator) available from
Celgard LLC.
[0064] When the separator 26 is a microporous polymeric separator,
it may be a single layer or a multi-layer laminate, which may be
fabricated from either a dry or a wet process. For example, in
certain instances, a single layer of the polyolefin may form the
entire separator 26. In other aspects, the separator 26 may be a
fibrous membrane having an abundance of pores extending between the
opposing surfaces and may have an average thickness of less than a
millimeter, for example. As another example, however, multiple
discrete layers of similar or dissimilar polyolefins may be
assembled to form the microporous polymer separator 26. The
separator 26 may also comprise other polymers in addition to the
polyolefin such as, but not limited to, polyethylene terephthalate
(PET), polyvinylidene fluoride (PVdF), a polyamide, polyimide,
poly(amide-imide) copolymer, polyetherimide, and/or cellulose, or
any other material suitable for creating the required porous
structure. The polyolefin layer, and any other optional polymer
layers, may further be included in the separator 26 as a fibrous
layer to help provide the separator 26 with appropriate structural
and porosity characteristics.
[0065] In certain aspects, the separator 26 may also be mixed with
a ceramic material or its surface may be coated in a ceramic
material. For example, a ceramic coating may include alumina
(Al.sub.2O.sub.3), silicon dioxide (SiO.sub.2), titania (TiO.sub.2)
or combinations thereof. In other variations, the separator 26 may
be coated within one or more coatings that are configured to block
polysulfide diffusion. For example, the separator 26 may include
KETJENBLACK.RTM. carbon-coated polypropylene (PP), carbon
nanotube-coated polypropylene (PP), graphene oxide-coated
polypropylene (PP), graphene-coated polypropylene (PP), MOF-coated
polypropylene (PP), MoS.sub.2-coated polypropylene (PP),
MoS.sub.2/carbon nanotube-coated polypropylene (PP), MnO-coated
polypropylene (PP), Li.sub.4Ti.sub.5O.sub.12/graphene-coated
polypropylene (PP), and the like. In still other variations, the
separator 26 may be polydopamine-coated polyolefin, Nafion-coated
polypropylene (PP), nanotube/polyethyleneglycol (PEG)-coated
polypropylene (PP), SiO.sub.2/polyethylene oxide (PEO)-coated
polypropylene (PP), and the like. Various conventionally available
polymers and commercial products for forming the separator 26 are
contemplated, as well as the many manufacturing methods that may be
employed to produce such a microporous polymer separator 26.
[0066] In various aspects, the porous separator 26 and the
electrolyte 100 in FIG. 1 may be replaced with a solid-state
electrolyte ("SSE") (not shown) that functions as both an
electrolyte and a separator. The solid-state electrolyte may be
disposed between the positive electrode 24 and negative electrode
22. The solid-state electrolyte facilitates transfer of lithium
ions, while mechanically separating and providing electrical
insulation between the negative and positive electrodes 22, 24. By
way of non-limiting example, solid-state electrolytes may include
LiTi.sub.2(PO.sub.4).sub.3, LiGe.sub.2(PO.sub.4).sub.3,
Li.sub.7La.sub.3Zr.sub.2O.sub.12, Li.sub.3xLa.sub.2/3-xTiO.sub.3,
Li.sub.3PO.sub.4, Li.sub.3N, Li.sub.4GeS.sub.4,
Li.sub.10GeP.sub.2S.sub.12, Li.sub.2S--P.sub.2S.sub.8,
Li.sub.6PS.sub.8Cl, Li.sub.6PS.sub.8Br, Li.sub.6PS.sub.5I,
Li.sub.3OCl, Li.sub.2.99 Ba.sub.0.005ClO, or combinations
thereof.
[0067] Each negative electrode 22 comprises a lithium material that
provides a lithium source that is capable of electrochemical
reactions with the sulfur-containing positive electroactive
material. For example, the negative electrodes 22 may include
negative electroactive materials that comprises lithium, such as,
for example, lithium metal. In certain variations, the negative
electrodes 22 include one or more films or layers formed of lithium
metal or an alloy of lithium. In certain variations, the negative
electrodes 22 may be defined by a plurality of negative
electroactive material particles (not shown). Such negative
electroactive material particles may be disposed in one or more
layers so as to define the three-dimensional structure of the
negative electrode 22. Other negative electroactive materials that
can also be used to form the negative electrodes 22, include, for
example, carbonaceous materials (such as graphite, hard carbon,
soft carbon), lithium-silicon and silicon containing binary and
ternary alloys and/or tin-containing alloys (such as Si, SiO.sub.x
Si--Sn, SiSnFe, SiSnAl, SiFeCo, SnO.sub.2, and the like), and/or
metal oxides (such as Fe.sub.3O.sub.4). In certain alternative
embodiments, lithium-titanium anode materials are contemplated,
such as Li.sub.4+xTi.sub.5O.sub.12, where 0.ltoreq.x.ltoreq.3,
including lithium titanate (Li.sub.4Ti.sub.5O.sub.12) (LTO). Such
electroactive materials should be lithiated.
[0068] In each instance, the negative electroactive material
defining the negative electrode 22 may be optionally intermingled
with one or more electrically conductive materials that provide an
electron conductive path and/or at least one polymeric binder
material that improves the structural integrity of the negative
electrode 22. For example, the negative electroactive material in
the negative electrode 22 may be optionally intermingled with
binders such as bare alginate salts, poly(tetrafluoroethylene)
(PTFE), sodium carboxymethyl cellulose (CMC), styrene-butadiene
rubber (SBR), poly(vinylidene fluoride) (PVDF), nitrile butadiene
rubber (NBR), styrene ethylene butylene styrene copolymer (SEBS),
styrene butadiene styrene copolymer (SBS), polyacrylate (PAA),
lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium
alginate, lithium alginate, ethylene propylene diene monomer
(EPDM), and combinations thereof. Electrically conductive materials
may include carbon-based materials, powder nickel or other metal
particles, or a conductive polymer. Carbon-based materials may
include, for example, particles of carbon black, graphite,
acetylene black (such as KETCHEN.TM. black or DENKA.TM. black),
carbon fibers and nanotubes (e.g., vapor grown carbon fibers
(VGCF)), graphene, graphene oxide, and the like. Examples of a
conductive polymer include polyaniline, polythiophene,
polyacetylene, polypyrrole, and the like.
[0069] For example, the negative electrodes 22 may each include
greater than or equal to about 30 wt. % to less than or equal to
about 99.5 wt. %, and in certain aspects, optionally greater than
or equal to about 50 wt. % to less than or equal to about 95 wt. %,
of the negative electroactive material; greater than or equal to
about 0 wt. % to less than or equal to about 30 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 15 wt. %, of one or more
electrically conductive materials; and greater than or equal to
about 0 wt. % to less than or equal to about 20 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 10 wt. %, of one or more binders.
The negative electrodes 22 may have thicknesses greater than or
equal to about 0.2 .mu.m to less than or equal to about 500
.mu.m.
[0070] Each positive electrode 24 may be defined by a plurality of
electroactive material particles (not shown) disposed in one or
more layers so as to define the three-dimensional structure of the
positive electrodes 24. For example, the positive electrodes 24 may
include a positive electroactive material that comprises sulfur.
For example, the positive electrode 24 may include a
sulfur-containing electroactive material and a sulfur host
material. The positive electrode 24 may include greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material, and greater than or equal
to 2 wt. % to less than or equal to about 60 wt. %, and in certain
aspects, optionally greater than or equal to about 10 wt. % to less
than or equal to about 30 wt. %, of the sulfur host material.
[0071] The sulfur-containing electroactive material may include,
for example only, S. The sulfur host material may be a carbon-based
host, including, for example only, carbon nanotubes, amorphous
carbon (e.g., carbon black, such as KETJENBLACK.RTM.), porous
carbon, carbon nanofibers, carbon spheres, carbon nanocage,
graphene, graphene oxide, reduced graphene oxide, doped carbon
(e.g., N-doped carbon nanotubes), and hybrids and the like. In
certain variations, the sulfur host material may be a conducting
polymer-based host, including, for example only, polyaniline (PAN),
polypyrrole (PPy), polythiophene (Pt), polyaniline (PAni),
poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS),
and the like. In other variations, the sulfur host material may be
a metal oxide-base host including, for example only, TiO.sub.2,
SiO.sub.2, CoS.sub.2, Ti.sub.4O.sub.7, CeO.sub.2, MoO.sub.3,
V.sub.2O.sub.5, SnO.sub.2, and the like; a metal sulfide-based host
including, for example only, Ni.sub.3S.sub.2, MoS.sub.2, FeS,
VS.sub.2, TiS.sub.2, TiS, CoS.sub.2, Co.sub.9S.sub.8, NbS, and the
like; a metal nitride-based host including, for example only, VN,
TiN, Ni.sub.2N, CrN, ZrN, NbN, and the like; metal carbide-based
host including, for example only, TiC, Ti.sub.2C, B.sub.4C, and the
like; metal organic framework (MOF)-based host including, for
example only, Ni-based-MOFs, Ce-based-MOFs, and the like; and
hybrids or combinations thereof (e.g., polypyrrole/graphene,
vanadium nitride/graphene, and the like). In still other
variations, the sulfur host material may include MgB.sub.2,
TiCl.sub.2, phosphorene, C.sub.3B, Li.sub.4Ti.sub.5O.sub.12, and
the like. Such sulfur host materials may enhance electron transfer
at the sulfur/host interface, accommodate volumetric changes within
the cell 20, minimize polysulfide shuttles, and/or promote
conversions among polysulfide intermediates.
[0072] The positive electroactive materials defining the positive
electrodes 24 may be optionally intermingled with an electronically
conducting material that provides an electron conduction path
and/or at least one polymeric binder material that improves the
structural integrity of the electrode. For example, the positive
electroactive materials and electronically or electrically
conducting materials may be slurry cast with such binders, like
polyvinylidene difluoride (PVdF), polytetrafluoroethylene (PTFE),
poly(ethylene oxide) (PEO), poly(vinylpyrrolidone) (PVP),
poly(ethylene glycol) (PEG), ethylene propylene diene monomer
(EPDM) rubber, or carboxymethyl cellulose (CMC), nitrile butadiene
rubber (NBR), styrene-butadiene rubber (SBR), styrene ethylene
butylene styrene copolymer (SEBS), styrene butadiene styrene
copolymer (SBS), polyacrylate (PAA), lithium polyacrylate (LiPAA),
sodium polyacrylate (NaPAA), sodium alginate, or lithium alginate.
Electrically conducting materials may include carbon-based
materials, powdered nickel or other metal particles (e.g., metal
wire and/or metal oxides), or a conductive polymer. Carbon-based
materials may include, for example, particles of graphite,
acetylene black (such as KETCHEN.TM. black or DENKA.TM. black),
carbon fibers and nanotubes (e.g., vapor grown carbon fibers
(VGCF)), graphene, graphene oxide, and the like. Examples of a
conductive polymer include polyaniline, polythiophene,
polyacetylene, polypyrrole, and the like. In certain aspects,
mixtures of the conductive materials may be used.
[0073] For example, each positive electrode 24 may include greater
than or equal to about 20 wt. % to less than or equal to about 98
wt. %, and in certain aspects, optionally greater than or equal to
about 60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material; greater than or equal to
about 2 wt. % to less than or equal to about 60 wt. %, and in
certain aspects, optionally greater than or equal to about 10 wt. %
to less than or equal to about 30 wt. %, of the sulfur host
material; greater than or equal to about 0 wt. % to less than or
equal to about 30 wt. %, and in certain aspects, optionally greater
than or equal to about 0.5 wt. % to less than or equal to about 15
wt. %, of one or more electrically conductive materials; and
greater than or equal to about 0 wt. % to less than or equal to
about 20 wt. %, and in certain aspects, optionally greater than or
equal to about 0.5 wt. % to less than or equal to about 10 wt. %,
of one or more binders. The positive electrodes 24 may have
thicknesses greater than or equal to about 1 .mu.m to less than or
equal to about 1000 .mu.m.
[0074] As noted above, the capacitor electrode 30 may be a positive
capacitor electrode (e.g., capacitor cathode), or in certain other
aspects, a negative capacitor electrode (e.g., capacitor anode), as
discussed below. The positive capacitor electrode 30 may have a
thickness greater than or equal to about 1 .mu.m to less than or
equal to about 1000 .mu.m, and in certain aspects, optionally
greater than or equal to about 20 .mu.m to less than or equal to
about 300 .mu.m. The positive capacitor electrode 30 may include a
capacitor active material, for example, a positive capacitor active
material. The positive capacitor active material may include, for
example only, activated carbon, graphene, carbon nanotubes, other
porous carbon materials, conducting polymers (e.g., PEDOT), and the
like.
[0075] The positive capacitor active material defining the positive
capacitor electrode 30 may be optionally intermingled with an
electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode. For example,
the positive capacitor active material and electronically or
electrically conducting materials may be slurry cast with such
binders, like polyvinylidene difluoride (PVdF),
polytetrafluoroethylene (PTFE), poly(ethylene oxide) (PEO),
poly(vinylpyrrolidone) (PVP), poly(ethylene glycol) (PEG), ethylene
propylene diene monomer (EPDM) rubber, or carboxymethyl cellulose
(CMC), nitrile butadiene rubber (NBR), styrene-butadiene rubber
(SBR), styrene ethylene butylene styrene copolymer (SEBS), styrene
butadiene styrene copolymer (SBS), polyacrylate (PAA), lithium
polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate,
or lithium alginate. Electrically conducting materials may include
carbon-based materials, powdered nickel or other metal particles
(e.g., metal wire and/or metal oxides), or a conductive polymer.
Carbon-based materials may include, for example, particles of
graphite, acetylene black (such as KETCHEN.TM. black or DENKA.TM.
black), carbon fibers and nanotubes (e.g., vapor grown carbon
fibers (VGCF)), graphene, graphene oxide, and the like. Examples of
a conductive polymer include polyaniline, polythiophene,
polyacetylene, polypyrrole, and the like. In certain aspects,
mixtures of the conductive materials may be used.
[0076] For example, the positive capacitor electrode 30 may include
greater than or equal to about 40 wt. % to less than or equal to
about 98 wt. %, and in certain aspects, optionally greater than or
equal to about 60 wt. % to less than or equal to about 95 wt. %, of
the positive capacitor active material; greater than or equal to
about 0 wt. % to less than or equal to about 30 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 15 wt. %, of one or more
electrically conductive materials; and greater than or equal to
about 0 wt. % to less than or equal to about 20 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 10 wt. %, of one or more
binders.
[0077] An exemplary and schematic illustration of another example
capacitor-assisted lithium-sulfur electrochemical cell (also
referred to as the battery 120 is shown in FIG. 2. Like the
capacitor-assisted lithium-sulfur battery 20 illustrated in FIG. 1,
the capacitor-assisted battery 120 includes a plurality of cells
110A-110C. Each cell 110A-110C includes a negative electrode 122
(e.g., anode), a positive electrode 124 (e.g., cathode), and a
separator 126 disposed between the two electrodes 122, 124. At
least one of the cells 110A-110C, includes a capacitor electrode
136 in place of one of the electrodes 122, 124. For example, as
illustrated, a capacitor electrode (e.g., lithium-ion capacitor
anode) 136 may be disposed in place of the anode 122 in a third
cell 110C. In each instance, the separator 126 provides electrical
separation (e.g., prevents physical contact) between the electrodes
122, 124, 136. In various aspects, the separator 126 comprises an
electrolyte 160 that may, in certain aspects, also be present in
the negative electrode 122, positive electrode 124, and/or
capacitor electrode 136.
[0078] Similar to battery 20, battery 120 includes one or more
negative electrode current collectors 132 and positive electrode
current collectors 134. A negative electrode current collector 132
may be positioned at or near each negative electrode 122 and/or
capacitor electrode 136, and a positive electrode current collector
134 may be positioned at or near each positive electrode 124. The
negative electrode current collectors 132 and the positive
electrode current collectors 134 respectively collect and move free
electrons to and from an external circuit 140. For example, an
interruptible external circuit 140 and a load device 142 may
connect the positive electrodes 124 (through the positive electrode
current collectors 134) and the negative electrodes 122 (through
the negative electrode current collectors 132) and/or capacitor
electrodes 136 (through the negative electrode current collectors
132).
[0079] Like negative electrodes 22, each negative electrode 122 may
include a negative electroactive material that comprises lithium,
such as, for example, lithium metal. In certain variations, the
negative electrodes 122 are films or layers formed of lithium metal
or an alloy of lithium. Like positive electrodes 24, each positive
electrode 124 may include a positive electroactive material that
comprises sulfur. The positive electrode 124 may include a
sulfur-containing electroactive material and a sulfur host
material. The positive electrode 124 may include greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material, and greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. %, and in
certain aspects, optionally greater than or equal to about 10 wt. %
to less than or equal to about 30 wt. %, of the sulfur host
material.
[0080] The capacitor electrode 136 may be a negative capacitor
electrode (e.g., capacitor anode). The capacitor electrode 136 may
have a thickness greater than or equal to about 1 .mu.m to less
than or equal to about 1000 .mu.m, and in certain aspects,
optionally greater than or equal to about 20 .mu.m to less than or
equal to about 300 .mu.m. The capacitor electrode 136 may include a
lithiated capacitor active material, for example, a lithiated
negative capacitor active material that provides lithium (e.g.,
lithium source) for the electrochemical reaction. The negative
capacitor active material may include, for example only, lithiated
activated carbon, lithiated soft carbon, lithiated hard carbon,
lithiated metal oxides, lithiated metal sulfides, and the like.
[0081] The lithiated negative capacitor active material defining
the negative capacitor electrode 136 may be optionally intermingled
with an electronically conducting material that provides an
electron conduction path and/or at least one polymeric binder
material that improves the structural integrity of the electrode.
For example, the negative capacitor active material and
electronically or electrically conducting materials may be slurry
cast with such binders, like polyvinylidene difluoride (PVdF),
polytetrafluoroethylene (PTFE), poly(ethylene oxide) (PEO),
poly(vinylpyrrolidone) (PVP), poly(ethylene glycol) (PEG), ethylene
propylene diene monomer (EPDM) rubber, or carboxymethyl cellulose
(CMC), nitrile butadiene rubber (NBR), styrene-butadiene rubber
(SBR), styrene ethylene butylene styrene copolymer (SEBS), styrene
butadiene styrene copolymer (SBS), polyacrylate (PAA), lithium
polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate,
or lithium alginate. Electrically conducting materials may include
carbon-based materials, powdered nickel or other metal particles
(e.g., metal wire and/or metal oxides), or a conductive polymer.
Carbon-based materials may include, for example, particles of
graphite, acetylene black (such as KETCHEN.TM. black or DENKA.TM.
black), carbon fibers and nanotubes (e.g., vapor grown carbon
fibers (VGCF)), graphene, graphene oxide, and the like. Examples of
a conductive polymer include polyaniline, polythiophene,
polyacetylene, polypyrrole, and the like. In certain aspects,
mixtures of the conductive materials may be used.
[0082] For example, the negative capacitor electrode 136 may
include greater than or equal to about 40 wt. % to less than or
equal to about 98 wt. %, and in certain aspects, optionally greater
than or equal to about 60 wt. % to less than or equal to about 90
wt. %, of the negative capacitor active material; greater than or
equal to about 0 wt. % to less than or equal to about 30 wt. %, and
in certain aspects, optionally greater than or equal to about 0.5
wt. % to less than or equal to about 15 wt. %, of one or more
electrically conductive materials; and greater than or equal to
about 0 wt. % to less than or equal to about 20 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 10 wt. %, of one or more
binders.
[0083] An exemplary and schematic illustration of another example
capacitor-assisted lithium-sulfur electrochemical cell (also
referred to as the battery) 220 is shown in FIG. 3. Like the
capacitor-assisted lithium-sulfur battery 20 illustrated in FIG. 1,
the capacitor-assisted lithium-sulfur battery 220 includes a
plurality of cells 210A-210C. Each cell 210A-210C includes a
negative electrode 222 (e.g., anode), a positive electrode 224
(e.g., cathode), and a separator 226 disposed between the two
electrodes 222, 224. At least one of the cells 210A-210C, includes
a capacitor electrode 230, 236 in place of one of the electrodes
222, 224. For example, as illustrated, a negative capacitor
electrode (e.g., lithium-ion capacitor anode) 236 may be disposed
in place of the anode 222 in the second cell 210B. Further, each
electrode 222, 224 in the first cell 210A may be replaced by
capacitor electrodes 230, 236. For example, the first cell 210A may
include a positive capacitor electrode 230, a negative capacitor
electrode 236, and a separator 236 disposed therebetween. In each
instance, the separator 226 provides electrical separation (e.g.,
prevents physical contact) between the electrodes 222, 224, 230,
236. In various aspects, the separator 226 comprises an electrolyte
260 that may, in certain aspects, also be present in the negative
electrode 222, positive electrode 224, and/or capacitor electrode
236.
[0084] Similar to battery 20, battery 220 includes one or more
negative electrode current collectors 232 and positive electrode
current collectors 234. A negative electrode current collector 232
may be positioned at or near each negative electrode 222 and/or
capacitor electrode 236, and a positive electrode current collector
234 may be positioned at or near each positive electrode 224. The
negative electrode current collectors 232 and the positive
electrode current collectors 234 respectively collect and move free
electrons to and from an external circuit 240. For example, an
interruptible external circuit 240 and a load device 242 may
connect the positive electrodes 224 (through the positive electrode
current collectors 234) and/or the positive capacitor electrodes
230 (through the positive electrode current collectors 234) and the
negative electrodes 222 (through the negative electrode current
collectors 232) and/or negative capacitor electrodes 236 (through
the negative electrode current collectors 232).
[0085] Like negative electrodes 22, each negative electrode 222
comprises a lithium host material may include a negative
electroactive material that comprises lithium, such as, for
example, lithium metal. In certain variations, the negative
electrodes 222 are films or layers formed of lithium metal or an
alloy of lithium. Like positive electrodes 24, each positive
electrode 224 may include a positive electroactive material that
comprises sulfur. The positive electrode 224 may include a
sulfur-containing electroactive material and a sulfur host
material. The positive electrode 224 may include greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material, and greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. %, and in
certain aspects, optionally greater than or equal to about 10 wt. %
to less than or equal to about 30 wt. %, of the sulfur host
material.
[0086] Like the positive capacitor electrode 30, the positive
capacitor electrode 230 may be a composite positive electrode
(e.g., capacitor cathode) comprising a positive capacitor active
material. For example, the positive capacitor electrode 230 may
include, for example only, activated carbon, graphene, carbon
nanotubes, other porous carbon materials, conducting polymers
(e.g., PEDOT), and the like. The positive capacitor electrode 230
may have a thickness greater than or equal to about 1 .mu.m to less
than or equal to about 1000 .mu.m, and in certain aspects,
optionally greater than or equal to about 20 .mu.m to less than or
equal to about 300 .mu.m.
[0087] The positive capacitor active material defining the positive
capacitor electrode 230 may be optionally intermingled with an
electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode. For example,
the positive capacitor electrode 230 may include greater than or
equal to about 40 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 95 wt. %, of the positive
capacitor active material; greater than or equal to about 0 wt. %
to less than or equal to about 30 wt. %, and in certain aspects,
optionally greater than or equal to about 0.5 wt. % to less than or
equal to about 15 wt. %, of one or more electrically conductive
materials; and greater than or equal to about 0 wt. % to less than
or equal to about 20 wt. %, and in certain aspects, optionally
greater than or equal to about 0.5 wt. % to less than or equal to
about 10 wt. %, of one or more binders.
[0088] Like the negative capacitor electrode 136, the negative
capacitor electrode 236 may be a composite negative electrode
(e.g., capacitor anode) comprising a negative capacitor active
material, for example, a lithiated negative capacitor active
material that provides lithium (e.g., lithium source) for the
electrochemical reaction. The negative capacitor active material
may include, for example only, lithiated activated carbon,
lithiated soft carbon, lithiated hard carbon, lithiated metal
oxides, lithiated metal sulfides, and the like. The negative
capacitor electrode 236 may have a thickness greater than or equal
to about 1 .mu.m to less than or equal to about 1000 .mu.m, and in
certain aspects, optionally greater than or equal to about 20 .mu.m
to less than or equal to about 300 .mu.m.
[0089] The negative capacitor active material defining the negative
capacitor electrode 236 may be optionally intermingled with an
electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode. For example,
the negative capacitor electrode 236 may include greater than or
equal to about 40 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 95 wt. %, of the negative
capacitor active material; greater than or equal to about 0 wt. %
to less than or equal to about 30 wt. %, and in certain aspects,
optionally greater than or equal to about 0.5 wt. % to less than or
equal to about 15 wt. %, of one or more electrically conductive
materials; and greater than or equal to about 0 wt. % to less than
or equal to about 20 wt. %, and in certain aspects, optionally
greater than or equal to about 0.5 wt. % to less than or equal to
about 10 wt. %, of one or more binders.
[0090] An exemplary and schematic illustration of another example
capacitor-assisted lithium-sulfur electrochemical cell (also
referred to as the battery) 320 is shown in FIG. 4. Like the
capacitor-assisted lithium-sulfur battery 20 illustrated in FIG. 1,
the capacitor-assisted lithium-sulfur battery 320 includes a
plurality of cells 310A-310C. Each cell 310A-310C includes a
negative electrode 322 (e.g., anode), a positive electrode 324
(e.g., cathode), and a separator 326 disposed between the two
electrodes 322, 324. At least one of the cells 310A-310C, includes
a capacitor electrode 330 in place of one of the electrodes 322,
324. For example, as illustrated, a positive capacitor electrode
(e.g., lithium-ion capacitor cathode) 330 may be disposed in place
of the cathode 324 in a second cell 310B so as to form an
asymmetric cathode electrode. In each instance, the separator 326
provides electrical separation (e.g., prevents physical contact)
between the electrodes 322, 324, 330. In various aspects, the
separator 326 comprises an electrolyte 360 that may, in certain
aspects, also be present in the negative electrode 322, positive
electrode 324, and/or positive capacitor electrode 330.
[0091] Similar to battery 20, battery 320 includes one or more
negative electrode current collectors 332 and positive electrode
current collectors 334. A negative electrode current collector 332
may be positioned at or near each negative electrode 322, and a
positive electrode current collector 334 may be positioned at or
near each positive electrode 324 and/or positive capacitor
electrode 330. The negative electrode current collectors 332 and
the positive electrode current collectors 334 respectively collect
and move free electrons to and from an external circuit 340. For
example, an interruptible external circuit 340 and a load device
342 may connect the negative electrodes 322 (through the negative
electrode current collectors 332) and the positive electrodes 324
(through the positive electrode current collectors 334) and/or
positive capacitor electrodes 330 (through the positive electrode
current collectors 334).
[0092] Like negative electrodes 22, each negative electrode 322
comprises a lithium host material may include a negative
electroactive material that comprises lithium, such as, for
example, lithium metal. In certain variations, the negative
electrodes 322 are films or layers formed of lithium metal or an
alloy of lithium. Like positive electrodes 24, each positive
electrode 324 may include a positive electroactive material that
comprises sulfur. The positive electrode 324 may include a
sulfur-containing electroactive material and a sulfur host
material. The positive electrode 324 may include greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material, and greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. %, and in
certain aspects, optionally greater than or equal to about 10 wt. %
to less than or equal to about 30 wt. %, of the sulfur host
material.
[0093] Like the positive capacitor electrode 30, the positive
capacitor electrode 330 may be a composite positive electrode
(e.g., capacitor cathode) comprising a positive capacitor active
material. For example, the positive capacitor electrode 330 may
include, for example only, activated carbon, graphene, carbon
nanotubes, other porous carbon materials, conducting polymers
(e.g., PEDOT), and the like. The positive capacitor electrode 330
may have a thickness greater than or equal to about 1 .mu.m to less
than or equal to about 1000 .mu.m, and in certain aspects,
optionally greater than or equal to about 20 .mu.m to less than or
equal to about 300 .mu.m.
[0094] The positive capacitor active material defining the positive
capacitor electrode 330 may be optionally intermingled with an
electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode. For example,
the positive capacitor electrode 330 may include greater than or
equal to about 40 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 95 wt. %, of the positive
capacitor active material; greater than or equal to about 0 wt. %
to less than or equal to about 30 wt. %, and in certain aspects,
optionally greater than or equal to about 0.5 wt. % to less than or
equal to about 15 wt. %, of one or more electrically conductive
materials; and greater than or equal to about 0 wt. % to less than
or equal to about 20 wt. %, and in certain aspects, optionally
greater than or equal to about 0.5 wt. % to less than or equal to
about 10 wt. %, of one or more binders.
[0095] An exemplary and schematic illustration of another example
capacitor-assisted lithium-sulfur electrochemical cell (also
referred to as the battery) 420 is shown in FIG. 5. Like the
capacitor-assisted lithium-sulfur battery 20 illustrated in FIG. 1,
the capacitor-assisted lithium-sulfur battery 420 includes a
plurality of cells 410A-410C. Each cell 410A-410C includes a
negative electrode 422 (e.g., anode), a positive electrode 424
(e.g., cathode), and a separator 426 disposed between the two
electrodes 422, 424. At least one of the cells 410A-410C, includes
a capacitor electrode 436 in place of one of the electrodes 422,
424. For example, as illustrated, a negative capacitor electrode
(e.g., lithium-ion capacitor anode) 436 may be disposed in place of
the anode 424 in a second cell 410B so as to form an asymmetric
anode electrode. In each instance, the separator 426 provides
electrical separation (e.g., prevents physical contact) between the
electrodes 422, 424, 436. In various aspects, the separator 426
comprises an electrolyte 460 that may, in certain aspects, also be
present in the negative electrode 422, positive electrode 424,
and/or negative capacitor electrode 436.
[0096] Similar to battery 20, battery 420 includes one or more
negative electrode current collectors 432 and positive electrode
current collectors 434. A negative electrode current collector 432
may be positioned at or near each negative electrode 422 and/or
negative capacitor electrode 436, and a positive electrode current
collector 434 may be positioned at or near each positive electrode
424. The negative electrode current collectors 432 and the positive
electrode current collectors 434 respectively collect and move free
electrons to and from an external circuit 440. For example, an
interruptible external circuit 440 and a load device 442 may
connect the positive electrodes 424 and the negative electrodes 422
(through the negative electrode current collectors 432) and/or
negative capacitor electrodes 436 (through the negative electrode
current collectors 432).
[0097] Like negative electrodes 22, each negative electrode 422
comprises a lithium host material may include a negative
electroactive material that comprises lithium, such as, for
example, lithium metal. In certain variations, the negative
electrodes 422 are films or layers formed of lithium metal or an
alloy of lithium. Like positive electrodes 24, each positive
electrode 424 may include a positive electroactive material that
comprises sulfur. The positive electrode 424 may include a
sulfur-containing electroactive material and a sulfur host
material. The positive electrode 424 may include greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material, and greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. %, and in
certain aspects, optionally greater than or equal to about 10 wt. %
to less than or equal to about 30 wt. %, of the sulfur host
material.
[0098] Like the negative capacitor electrode 136, the negative
capacitor electrode 436 may be a composite negative electrode
(e.g., capacitor anode) comprising a negative capacitor active
material, for example, a lithiated negative capacitor active
material that provides lithium (e.g., lithium source) for the
electrochemical reaction. The negative capacitor active material
may include, for example only, lithiated activated carbon,
lithiated soft carbon, lithiated hard carbon, lithiated metal
oxides, lithiated metal sulfides, and the like. The negative
capacitor electrode 436 may have a thickness greater than or equal
to about 1 .mu.m to less than or equal to about 1000 .mu.m, and in
certain aspects, optionally greater than or equal to about 20 .mu.m
to less than or equal to about 300 .mu.m.
[0099] The negative capacitor active material defining the negative
capacitor electrode 436 may be optionally intermingled with an
electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode. For example,
the negative capacitor electrode 436 may include greater than or
equal to about 40 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 95 wt. %, of the negative
capacitor active material; greater than or equal to about 0 wt. %
to less than or equal to about 30 wt. %, and in certain aspects,
optionally greater than or equal to about 0.5 wt. % to less than or
equal to about 15 wt. %, of one or more electrically conductive
materials; and greater than or equal to about 0 wt. % to less than
or equal to about 20 wt. %, and in certain aspects, optionally
greater than or equal to about 0.5 wt. % to less than or equal to
about 10 wt. %, of one or more binders.
[0100] An exemplary and schematic illustration of another example
capacitor-assisted lithium-sulfur electrochemical cell (also
referred to as the battery) 520 is shown in FIG. 6. Like the
lithium-sulfur capacitor-assisted battery 20 illustrated in FIG. 1,
the capacitor-assisted lithium-sulfur battery 520 includes a
plurality of cells 510A-510C. Each cell 510A-510C includes a
negative electrode 522 (e.g., anode), a positive electrode 524
(e.g., cathode), and a separator 526 disposed between the two
electrodes 522, 524. One or more of the cells 510A-510C includes a
capacitor-based interlayer 530 disposed between the separator 526
and one of the negative electrode 522 and/or positive electrode
524. For example, as illustrated, a first capacitor-based
interlayer 530 may be disposed between the positive electrode 524
and the separator 526 in the first cell 510A; a second
capacitor-based interlayer 530 may be disposed between the positive
electrode 524 and the separator 526 in the second cell 510B; and a
third capacitor-based interlayer 530 may be disposed between the
positive electrode 524 and the separator 526 in the third cell
510C. In each instance, the separator 526 provides electrical
separation (e.g., prevents physical contact) between the electrodes
522, 524 and/or interlayer 530. In various aspects, the separator
526 comprises an electrolyte 560 that may, in certain aspects, also
be present in the negative electrode 522, positive electrode 524,
and/or capacitor-base interlayer 530.
[0101] The capacitor-based interlayer 530 has a thickness greater
than or equal to about 0.1 .mu.m to less than or equal to about 100
.mu.m and comprises a capacitor active material. The capacitor
active material may be a positive capacitor active material. The
positive capacitor active material may include, for example only,
activated carbon, graphene, carbon nanotubes, other porous carbon
materials, conducting polymers (e.g., PEDOT), and the like. The
positive capacitor active material defining capacitor-based
interlayer 530 may be optionally intermingled with an
electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode.
[0102] For example, the capacitor-based interlayer 530 may include
greater than or equal to about 40 wt. % to less than or equal to
about 98 wt. %, and in certain aspects, optionally greater than or
equal to about 60 wt. % to less than or equal to about 95 wt. %, of
the positive capacitor active material; greater than or equal to
about 0 wt. % to less than or equal to about 30 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 15 wt. %, of one or more
electrically conductive materials; and greater than or equal to
about 0 wt. % to less than or equal to about 20 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 10 wt. %, of one or more binders.
The capacitor-based interlayer 530 may be formed by coating the
interlayer 530 onto one of the positive electrode 524 and the
separator 526.
[0103] Similar to battery 20, battery 520 includes one or more
negative electrode current collectors 532 and positive electrode
current collectors 534. A negative electrode current collector 532
may be positioned at or near each negative electrode 522, and a
positive electrode current collector 534 may be positioned at or
near each positive electrode 524. The negative electrode current
collectors 532 and the positive electrode current collectors 534
respectively collect and move free electrons to and from an
external circuit 540. For example, an interruptible external
circuit 540 and a load device 542 may connect the positive
electrodes 524 (through the positive electrode current collectors
534) and the negative electrodes 522 (through the negative
electrode current collectors 532).
[0104] Like negative electrodes 22, each negative electrode 522
comprises a lithium host material may include a negative
electroactive material that comprises lithium, such as, for
example, lithium metal. In certain variations, the negative
electrodes 522 are films or layers formed of lithium metal or an
alloy of lithium. Like positive electrodes 24, each positive
electrode 524 may include a positive electroactive material that
comprises sulfur. The positive electrode 524 may include a
sulfur-containing electroactive material and a sulfur host
material. The positive electrode 524 may include greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material, and greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. %, and in
certain aspects, optionally greater than or equal to about 10 wt. %
to less than or equal to about 30 wt. %, of the sulfur host
material.
[0105] An exemplary and schematic illustration of another example
capacitor-assisted lithium-sulfur electrochemical cell (also
referred to as the battery) 620 is shown in FIG. 7. Like the
capacitor-assisted lithium-sulfur battery 20 illustrated in FIG. 1,
the capacitor-assisted lithium-sulfur battery 620 includes a
plurality of cells 610A-610C. Each cell 610A-610C includes a
negative electrode 622 (e.g., anode), a positive electrode 624
(e.g., cathode), and a separator 626 disposed between the two
electrodes 622, 624. One or more of the cells 610A-610C includes a
capacitor-based interlayer 636 disposed between the separator 626
and one of the negative electrode 622 and/or positive electrode
624. For example, as illustrated, a first capacitor-based
interlayer 630 may be disposed between the negative electrode 622
and the separator 626 in the first cell 610A; a second
capacitor-based interlayer 630 may be disposed between the negative
electrode 622 and the separator 626 in the second cell 610B; and a
third capacitor-based interlayer 630 may be disposed between the
negative electrode 622 and the separator 626 in the third cell
610C. In each instance, the separator 626 provides electrical
separation (e.g., prevents physical contact) between the electrodes
622, 624 and/or interlayer 636. In various aspects, the separator
626 comprises an electrolyte 660 that may, in certain aspects, also
be present in the negative electrode 622, positive electrode 624,
and/or negative capacitor electrode 636.
[0106] The capacitor-based interlayer 636 has a thickness greater
than or equal to about 0.1 .mu.m to less than or equal to about 100
.mu.m and comprises a capacitor active material. The capacitor
active material may be a negative capacitor active material. The
negative capacitor active material may include, for example only,
lithiated activated carbon, lithiated soft carbon, lithiated hard
carbon, lithiated metal oxides, lithiated metal sulfides, and the
like. The negative capacitor active material defining
capacitor-based interlayer 636 may be optionally intermingled with
an electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode.
[0107] For example, the capacitor-based interlayer 636 may include
greater than or equal to about 40 wt. % to less than or equal to
about 98 wt. %, and in certain aspects, optionally greater than or
equal to about 60 wt. % to less than or equal to about 95 wt. %, of
the negative capacitor active material; greater than or equal to
about 0 wt. % to less than or equal to about 30 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 15 wt. %, of one or more
electrically conductive materials; and greater than or equal to
about 0 wt. % to less than or equal to about 20 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 10 wt. %, of one or more binders.
The capacitor-based interlayer 636 may be formed by coating the
interlayer 636 onto one of the negative electrode 622 and the
separator 626.
[0108] Similar to battery 20, battery 620 includes one or more
negative electrode current collectors 632 and positive electrode
current collectors 634. A negative electrode current collector 632
may be positioned at or near each negative electrode 622, and a
positive electrode current collector 634 may be positioned at or
near each positive electrode 624. The negative electrode current
collectors 632 and the positive electrode current collectors 634
respectively collect and move free electrons to and from an
external circuit 640. For example, an interruptible external
circuit 640 and a load device 642 may connect the positive
electrodes 624 (through the positive electrode current collectors
634) and the negative electrodes 622 (through the negative
electrode current collectors 632).
[0109] Like negative electrodes 22, each negative electrode 622
comprises a lithium host material may include a negative
electroactive material that comprises lithium, such as, for
example, lithium metal. In certain variations, the negative
electrodes 622 are films or layers formed of lithium metal or an
alloy of lithium. Like positive electrodes 24, each positive
electrodes 624 may include a positive electroactive material that
comprises sulfur. The positive electrode 624 may include a
sulfur-containing electroactive material and a sulfur host
material. The positive electrode 624 may include greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material, and greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. %, and in
certain aspects, optionally greater than or equal to about 10 wt. %
to less than or equal to about 30 wt. %, of the sulfur host
material.
[0110] An exemplary and schematic illustration of another example
capacitor-assisted lithium-sulfur electrochemical cell (also
referred to as the battery) 720 is shown in FIG. 8. Like the
capacitor-assisted lithium-sulfur battery 20 illustrated in FIG. 1,
the capacitor-assisted lithium-sulfur battery 720 includes a
plurality of cells 710A-710C. Each cell 710A-710C includes a
negative electrode 722 (e.g., anode), a positive electrode 724
(e.g., cathode), and a separator 726 disposed between the two
electrodes 722, 724. One or more of the cells 710A-710C includes
one or more capacitor-based interlayers 730, 736 disposed between
the separator 726 and one of the negative electrode 722 and/or
positive electrode 724. For example, as illustrated, a first
positive capacitor-based interlayer 730 may be disposed between the
positive electrode 724 and the separator 726 and a first negative
capacitor-based interlayer 736 may be disposed between the negative
electrode 722 and the separator 726 in the first cell 710A; a
second positive capacitor-based interlayer 730 may be disposed
between the positive electrode 724 and the separator 726 and a
second negative capacitor-based interlayer 736 may be disposed
between the negative electrode 722 and the separator 726 in the
second cell 710B; and a third positive capacitor-based interlayer
730 may be disposed between the positive electrode 724 and the
separator 726 and a third negative capacitor-based interlayer 736
may be disposed between the negative electrode 722 and the
separator 726 in the third cell 710C.
[0111] The positive capacitor-based interlayer 730 has a thickness
greater than or equal to about 0.1 .mu.m to less than or equal to
about 100 .mu.m and comprises a positive capacitor active material.
The positive capacitor active material may include, for example
only, activated carbon, graphene, carbon nanotubes, other porous
carbon materials, conducting polymers (e.g., PEDOT), and the like.
The positive capacitor active material defining capacitor-based
interlayer 730 may be optionally intermingled with an
electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode.
[0112] For example, the positive capacitor-based interlayer 730 may
include greater than or equal to about 40 wt. % to less than or
equal to about 98 wt. %, and in certain aspects, optionally greater
than or equal to about 60 wt. % to less than or equal to about 95
wt. %, of the positive capacitor active material; greater than or
equal to about 0 wt. % to less than or equal to about 30 wt. %, and
in certain aspects, optionally greater than or equal to about 0.5
wt. % to less than or equal to about 15 wt. %, of one or more
electrically conductive materials; and greater than or equal to
about 0 wt. % to less than or equal to about 20 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 10 wt. %, of one or more binders.
The capacitor-based interlayer 730 may be formed by coating the
interlayer 730 onto one of the positive electrode 724 and the
separator 726.
[0113] The negative capacitor-based interlayer 736 has a thickness
greater than or equal to about 0.1 .mu.m to less than or equal to
about 100 .mu.m and comprises a negative capacitor active material.
The negative capacitor active material may include, for example
only, lithiated activated carbon, lithiated soft carbon, lithiated
hard carbon, lithiated metal oxides, lithiated metal sulfides, and
the like. The negative capacitor active material defining
capacitor-based interlayer 736 may be optionally intermingled with
an electronically conducting material that provides an electron
conduction path and/or at least one polymeric binder material that
improves the structural integrity of the electrode.
[0114] For example, the negative capacitor-based interlayer 736 may
include greater than or equal to about 40 wt. % to less than or
equal to about 98 wt. %, and in certain aspects, optionally greater
than or equal to about 60 wt. % to less than or equal to about 95
wt. %, of the negative capacitor active material; greater than or
equal to about 0 wt. % to less than or equal to about 30 wt. %, and
in certain aspects, optionally greater than or equal to about 0.5
wt. % to less than or equal to about 15 wt. %, of one or more
electrically conductive materials; and greater than or equal to
about 0 wt. % to less than or equal to about 20 wt. %, and in
certain aspects, optionally greater than or equal to about 0.5 wt.
% to less than or equal to about 10 wt. %, of one or more binders.
The negative capacitor-based interlayer 736 may be formed by
coating the interlayer 736 onto one of the negative electrode 722
and the separator 726.
[0115] Similar to battery 20, battery 720 includes one or more
negative electrode current collectors 732 and positive electrode
current collectors 734. A negative electrode current collector 732
may be positioned at or near each negative electrode 722, and a
positive electrode current collector 734 may be positioned at or
near each positive electrode 724. The negative electrode current
collectors 732 and the positive electrode current collectors 734
respectively collect and move free electrons to and from an
external circuit 740. For example, an interruptible external
circuit 740 and a load device 742 may connect the positive
electrodes 724 (through the positive electrode current collectors
734) and the negative electrodes 722 (through the negative
electrode current collectors 732).
[0116] Like negative electrodes 22, each negative electrode 722
comprises a lithium host material may include a negative
electroactive material that comprises lithium, such as, for
example, lithium metal. In certain variations, the negative
electrodes 722 are films or layers formed of lithium metal or an
alloy of lithium. Like positive electrodes 24, each positive
electrodes 724 may include a positive electroactive material that
comprises sulfur. The positive electrode 724 may include a
sulfur-containing electroactive material and a sulfur host
material. The positive electrode 724 may include greater than or
equal to about 20 wt. % to less than or equal to about 98 wt. %,
and in certain aspects, optionally greater than or equal to about
60 wt. % to less than or equal to about 90 wt. %, of the
sulfur-containing electroactive material, and greater than or equal
to about 2 wt. % to less than or equal to about 60 wt. %, and in
certain aspects, optionally greater than or equal to about 10 wt. %
to less than or equal to about 30 wt. %, of the sulfur host
material.
[0117] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be
included within the scope of the disclosure.
* * * * *